Mercury Exposure in Humboldt (Spheniscus humboldti) and Chinstrap (Pygoscelis antarcticus) Penguins Throughout the Chilean Coast and Antarctica

Abstract

Penguins are reliable sentinels for environmental assessments of mercury (Hg) due to their longevity, abundance, high trophic level, and relatively small foraging areas. We analyzed Hg concentrations from blood and feathers of adult Humboldt penguins (Spheniscus humboldti) and feathers of chinstrap penguins (Pygoscelis antarcticus) from different reproductive colonies with variable degrees of urbanization and industrialization along the Chilean and Antarctic coasts. We evaluated Hg concentration differences between species, sexes (Humboldt penguins), and localities. Our results showed significantly greater levels in Humboldt penguins than in chinstrap penguins and nonsignificant differences between sexes among Humboldts. Penguin Hg concentrations showed a latitudinal pattern, with greater values of the metal at lower latitudes, independent of the species. Both studied penguin species showed elevated Hg concentrations compared to their congeners, highlighting the necessity to investigate potential negative effects on their populations. Although differences between species are possibly due to variation in diet and trophic level, our results suggest an important effect of the degree of Hg pollution adjacent to foraging areas. Further research on Hg content in prey species and environmental samples, together with a larger overall sample size, and investigation on penguin's diet and trophic level are needed to elucidate Hg bioavailability in each location and the role of local Hg pollution levels. Likewise, it is important to monitor Hg and other heavy metals of ecotoxicological importance in penguin populations in vulnerable regions of Chile.

Influence of Species‐Specific Feeding Ecology on Mercury Concentrations in Seabirds Breeding on the Chatham Islands, New Zealand

“…The high productivity of the Humboldt Current system is likely to result in a dilution of Hg in the system and would limit marine predator's exposure. Very few data are available regarding the Hg exposure of seabirds foraging in the Humboldt Current region (Gochfeld 1980; Álvarez‐Varas et al 2018). Relatively low Hg breast feather levels between 0.5 and 2.0 µg g –1 dry weight were found in piscivorous species sampled on the Peruvian coast (Gochfeld 1980).…”

Microorganisms isolated from seabirds feathers for mercury bioremediation

“…Seabirds' bioaccumulation mercury has been repor-ted from different locations in the Antarctic and including in petrel feathers Pagodroma nivea 0.54 ± 0.18 μg g−1 dry wt 18 , antarctic petrel Thalassoica antarctica 2.71 ± 0.25 mg g-1 dw 39 ; Gentoo penguins Pygoscelis papua 1.83 ± 0.80 ug g−1 dw 31,[40][41][42] , Chinstrap penguins Pygoscelis antarctica 1.53 ± 0.08 ug g−1 dw 31,40,41 , Pygoscelis adeliae 0.82 to 1.40 ± 0.13 μg g−1 dw 18,40,41 , Aptenodytes forsten 0.98 ± 0.2 μg g−1 dw; skuas Catharacta maccormicki 2.91 ± 1.93 µg g -1 dw 18 , Catharacta lonnbergi 2.86 ± 2.60 ug g−1 dw 31 and gull Larus dominicanus 426.6 ng g−1 9 .…”

Humboldt penguins' feathers as bioindicators of metal exposure

“…However, the majority of investigations have only focused on mercury levels in feathers (e.g. Álvarez-Varas et al, 2018;Becker et al, 2016;Brasso et al, 2015;Carravieri et al, 2013;Frias et al, 2012).…”

“…This is the first study aimed at investigating metal transfer of 18 trace elements from food to feathers in this species; moreover, investigations regarding metals in S. humboldti are very scarce. In fact, to our knowledge, only mercury levels have been investigated, by Álvarez-Varas et al (2018) in Humboldt feathers from the Chilean and Antarctic coasts, while the concentrations of six metals (arsenic, cadmium, copper mercury, lead and zinc) have been investigated in Humboldt excreta from the northern coast of Chile (Celis et al 2014).…”